Washington —
All four of Florida Power & Light's nuclear units - St. Lucie-1 and -2 and Turkey Point-3 and -4 - operated at 100% of capacity August 30 through Tuesday as Hurricane Dorian stalled off the state's coast, according to FPL spokesman Matthew Eissey.

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FPL has two nuclear plants of two units each on south Florida's Atlantic Coast: the 1,770-MW Turkey Point plant in Homestead and the 2,213-MW St. Lucie plant in Jensen Beach.

"We will continue to monitor the storm," Eissey said in an email Tuesday.

FPL classified the status of St. Lucie-1 and -2 as undergoing an "unusual event" emergency Sunday ahead of the arrival of Dorian, US Nuclear Regulatory Commission spokesman Joey Ledford said in an email Tuesday.

An unusual event is the lowest of four classifications of power reactor emergencies used by NRC.

"A hurricane warning is in effect for the St. Lucie plant site," FPL said in its notice at 5:17 pm EDT Sunday.

Dorian has been as strong as a Category 5 storm, with winds greater than 155 mph, and is now a Category 2 storm with maximum sustained winds of 110 mph, according to a report issued by the US Department of Commerce's National Oceanic and Atmospheric Administration.

The system will move "dangerously close" to Florida's east coast late Tuesday through Wednesday evening, NOAA said.

"If hurricane-force winds are expected at the [St. Lucie plant] site, we would follow our conservative procedures and the units would be shut down well in advance," Eissey said in an email Monday.

It is a regulatory requirement that US nuclear units must shut at least two hours before the projected arrival of sustained hurricane-force winds above 74 mph. Nuclear reactors are designed to withstand extreme winds, including tornado-strength gusts, but shut as a protective measure in case off-site power is lost during a storm.

However, "current detailed forecasting does not have the plant weathering even tropical storm strength winds," Ledford said in an email Tuesday.

An unusual event had not been declared at Turkey Point Tuesday.

FPL is working through a very detailed storm preparation procedure, Ledford said in an August 30 email. "That work includes checking equipment and supplies such as diesel generator fuel, securing or moving other equipment or items that might be blown around, and implementing a staffing plan to ensure enough operators and support staff are on site around the clock if roads become inaccessible," he said.

FPL spokesman Peter Robbins said August 30 that FPL had been making emergency response preparations at the two nuclear plants since August 26.